vercel/next.js · error

Your project has both `sass` and `node-sass` installed as de

Error message

Your project has both `sass` and `node-sass` installed as dependencies, but should only use one or the other. Please remove the `node-sass` dependency from your project.  Read more: https://nextjs.org/docs/messages/duplicate-sass

What it means

Error "Your project has both `sass` and `node-sass` installed as dependencies, but should only use one or the other. Please remove the `node-sass` dependency from your project. Read more: https://nextjs.org/docs/messages/duplicate-sass" thrown in vercel/next.js.

Source

Thrown at packages/next/src/cli/next-dev.ts:237

  }

  if (options.experimentalCpuProf) {
    Log.info(
      `CPU profiling enabled. Profile will be saved to .next-profiles/ on exit (Ctrl+C).`
    )
  }

  async function preflight(skipOnReboot: boolean) {
    const { getPackageVersion, getDependencies } = (await Promise.resolve(
      require('../lib/get-package-version') as typeof import('../lib/get-package-version')
    )) as typeof import('../lib/get-package-version')

    const [sassVersion, nodeSassVersion] = await Promise.all([
      getPackageVersion({ cwd: dir, name: 'sass' }),
      getPackageVersion({ cwd: dir, name: 'node-sass' }),
    ])
    if (sassVersion && nodeSassVersion) {
      Log.warn(
        'Your project has both `sass` and `node-sass` installed as dependencies, but should only use one or the other. ' +
          'Please remove the `node-sass` dependency from your project. ' +
          ' Read more: https://nextjs.org/docs/messages/duplicate-sass'
      )
    }

    if (!skipOnReboot) {
      const { dependencies, devDependencies } = await getDependencies({
        cwd: dir,
      })

      // Warn if @next/font is installed as a dependency. Ignore `workspace:*` to not warn in the Next.js monorepo.
      if (
        dependencies['@next/font'] ||
        (devDependencies['@next/font'] &&
          devDependencies['@next/font'] !== 'workspace:*')
      ) {
        const command = getNpxCommand(dir)

View on GitHub (pinned to 0eb3775416)

Solutions

1. Remove `node-sass` from your dependencies and keep only `sass`.

When it happens

Trigger: Thrown at packages/next/src/cli/next-dev.ts:237 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of vercel/next.js@0eb3775416 (2026-08-19). Data as JSON: /api/errors/fc212da1af13a0ca. Report an issue: GitHub.